The present invention relates to a radiation CT system such as an X-ray CT system, a data acquisition system, and a data acquisition method.
Radiation CT systems employing a multi-array detector that has a plurality of detector elements set in array in a direction of channels and in a direction of slices alike are known (refer to, for example, Patent Document 1). Output signals of the detector elements are amplified by amplifiers included in a data acquisition system (DAS). In general, the number of amplifiers is the same as the number of detector elements (the number of channels by the number of arrays juxtaposed in the direction of slices).
Patent Document 1 describes that four data acquisition systems (DASs) are used in combination with a multi-array detector having eight arrays of detector elements juxtaposed in the direction of slices, that the connections between the arrays of detector elements and the data acquisition systems are changed based on a slice thickness, and that one amplifier amplifies outputs of two arrays of detector elements. Herein, the connections are changed from ones to others prior to scanning, and two arrays of detector elements are treated as one array of detector elements. This is equivalent to a case where the same number of amplifiers as the number of detector elements is included.
[Patent Document 1] Japanese Unexamined Patent Publication No. 2001-212128
As for a multi-array detector, an increase in the number of arrays of detector elements juxtaposed in the direction of slices or realization of finer detector elements, that is, an increase in the number of detector elements is demanded from the viewpoint of a shorter scan time or improved image quality. On the other hand, amplifiers are included in a data acquisition system in association with all detector elements. The number of amplifiers increases along with an increase in the number of detector elements, whereby various drawbacks take place. For example, it is hard to preserve a space in which the amplifiers are disposed, a power consumption increases, an amount of dissipated heat increases, and a cost increases.